I just installed an Amsoil dual by-pass system on my truck that also relocates the FF. But the FF that the kit requires uses 3/4" threads instead of the 22mm that the truck originally uses. So I'd like to know if the reduced size of the center hole on the filter I'm using now will flow less than the one that came with the truck from the factory? Thanks.
Oil filter flow 22mm vs 3/4"?
- Thread starter chico80x
- Start date
- Status
Yes...
Well sorta..
Had this discussion with engineering. It seems the Big 3 in Detroit are looking at going to 22mm to allow more flow at "redline"..
Make of that what you will..
Doesn't mean they will mind you..just that they are considering it.
Well sorta..
Had this discussion with engineering. It seems the Big 3 in Detroit are looking at going to 22mm to allow more flow at "redline"..
Make of that what you will..
Doesn't mean they will mind you..just that they are considering it.
- Joined
- Sep 28, 2002
- Messages
- 39,799
Measure the holes in your OEM spec'd filter and add up the area(s). It should be less then 3/4^2". Any reductions in net flow would have to elevate the pressure at the pump above the pressure relief limit. Otherwise the oil just moves faster through any choke. This is surely possible ..but in practice appears to be rare.
Shoot, the ID of the hose on that kit is even smaller at 13/32". Even the higher flowing marine kit uses 1/2" ID hose. That and the fittings on the mount are 3/4-16 "o-ring". Best would be to adapt that to some higher flowing Earls plumbing in the -8 to -10 range (-12 would be better but again you are limited to the realatively small 3/4-16 ports...)
These small ports are my only reservation keeping me from buying this kit. My application uses 20x1.5.
These small ports are my only reservation keeping me from buying this kit. My application uses 20x1.5.
Gary,a re you thinking the intake holes in the filter?
- Joined
- Sep 28, 2002
- Messages
- 39,799
Yep. If you look at various offerings ..they differ. Some have many ..some have few...small ..big ..but all seem to work.
Under the relief limit of the pump ..the oil merely accellerates. Just like a rapids in a river. The gpm stays the same ..just the intermediate velocity changes.
Under the relief limit of the pump ..the oil merely accellerates. Just like a rapids in a river. The gpm stays the same ..just the intermediate velocity changes.
If the surface area of the inlet holes exceeds the outlet surface area..then the outlet reduces flow. ( relatively).
If the outlet surface area is larger than the inlet hole surface area..then the inlet reduces flow. ( relatively)
Generally it is the outlet surface area which can have the slightly smaller surface area rather than the inlet.
If the outlet surface area is larger than the inlet hole surface area..then the inlet reduces flow. ( relatively)
Generally it is the outlet surface area which can have the slightly smaller surface area rather than the inlet.
If the outlet is the reduction then 20mm is larger than the 13/32" hose on the Amsoil kit.
- Joined
- Sep 28, 2002
- Messages
- 39,799
If he's got a dual filter setup ..he's not using a Dual Guard with two bypass filters. That the setup that uses the itty-bitty hoses.
I'm looking at an ST 3614 and, depending on the wall thickness of the stud, the inlet holes easily fit inside the filter's threaded hole ..with plenty to spare.
In ANY EVENT ..regardless of the "chokes" ...you get ABSOLUTELY NO CHANGE IN FLOW UNLESS THERE IS AN OPENING OF THE OIL PUMP'S RELIEF VALVE (pump losses excluded). It doesn't matter if you have a .0000001" opening ..or 70 weight oil @ -50F through TP filters. That condition must be present for flow reduction.
Naturally any of those conditions would probably open the oil pump's relief valve ..but you've got to understand that one fundamental truth before you can speculate on variations in flow.
I'm looking at an ST 3614 and, depending on the wall thickness of the stud, the inlet holes easily fit inside the filter's threaded hole ..with plenty to spare.
In ANY EVENT ..regardless of the "chokes" ...you get ABSOLUTELY NO CHANGE IN FLOW UNLESS THERE IS AN OPENING OF THE OIL PUMP'S RELIEF VALVE (pump losses excluded). It doesn't matter if you have a .0000001" opening ..or 70 weight oil @ -50F through TP filters. That condition must be present for flow reduction.
Naturally any of those conditions would probably open the oil pump's relief valve ..but you've got to understand that one fundamental truth before you can speculate on variations in flow.
Flow is not proportional to area, more like the fourth or fifth power. If a hole is half as big, it will at least 16 of them to equal the flow of the larger one.
The kit I installed in my truck is the BMK-13 and the hoses are indeed even smaller than the opening on the filter. One thing I did do is use the second to largest filter I was able to on this mount but instead of using and Amsoil, I bought a PureOne 30001 which is 5.14" in height and 3.78" in diameter. Right now everything seems to be ok because I have no leaks and even though I don't know if the pressure gauge that came with my truck tells me the pressure before or after the filter, it's still showing that I have the same amount of pressure I had before the installation.
- Joined
- Sep 28, 2002
- Messages
- 39,799
Flow is proportional to area. It's not proportional to diameter. 50% increase in diameter effectively doubles the area (close enough for me to say it that way).
I don't think that we're in disagreement with further consideration of what was said.
Picky ain't ya'....
- Joined
- Sep 28, 2002
- Messages
- 39,799
(insert Jhackeh Stoowaht accent)
I dunnoah
I donnah think so
Thenahgain ..yoo're askin for ah self critique. It'sah always biased
I dunnoah
True, flow may not be affected but due to friction loss PRESSURE can definately be decreased. Smaller diameter oil line will have more of a psi loss than a larger diameter line (including loss from fittings, etc.) Just don't know why Amsoil uses such small hoses (as compared to the orafices in the filters) in the BMK-13? You got a 3/4" plus inlet from the factory filter to the engine and a 3/4" inlet in the Amsoil filter but only a 13/32" hose conecting all of it together- along with longer hose spans contributing even more to the friction loss...
Was also just thinking on a somewhat unrelated note...
I don't think I would mount a remote kit above the height of the factory filter outlet. The filter may have an anti-drainback valve but I bet the oil in the line BEFORE the mount would drain back through the pump into the pan. Each time you fire up the engine has to fill the line up to the filters. Again, another reason for short hose runs.
Anyone see a flaw in this logic?
I don't think I would mount a remote kit above the height of the factory filter outlet. The filter may have an anti-drainback valve but I bet the oil in the line BEFORE the mount would drain back through the pump into the pan. Each time you fire up the engine has to fill the line up to the filters. Again, another reason for short hose runs.
Anyone see a flaw in this logic?
- Joined
- Sep 28, 2002
- Messages
- 39,799
No, you're correct. I had to install check valves to not have my remote drain back ..and forward. It's not as bad with strictly bypass mounts since they can't pass too much oil anyway.
Oops! Must fess up. I looked up the equations for flow through a hole, and I WAS WRONG. They are quite different from flow in a pipe. Flow is proportional to the area of a hole. So adding up the area of the holes is valid. Make note of this, Labman admitted he was wrong. First mistake I ever made.
However it may not be valid to compare it to the cross section of the stud. As the path becomes long as compared to the diameter, you then must switch to the equations that use the fourth or fifth power of the diameter. The small lines mentioned in another post are quite restrictive.
Getting back to the studs. 3/4'' is 19 mm, not that much smaller than your 20 mm. If the ID is about the same 95% as the OD, then 0.95^4 = 0.81. At a given back pressure, you would have 81% of the flow, or about 20% more back pressure. Applying the same assumptions to a 22 mm stud, 22/19 = 1.16. 1.16^4 = 1.8, or 80% more flow at the same back pressure switching to a 22 mm stud.
- Joined
- Sep 28, 2002
- Messages
- 39,799
Well, labman ...we're sorta dealing with orifices ..which react a little differently then conduits ..but no matter. You don't have the length component to factor ..but the difference between laminar and turbulant flow screws things up. You weren't "wrong" in any other manner then saying area vs. diameter (1/2" pipe is to 3/4" pipe vs. what .75^" pipe vs. .5^" pipe).
Did I sound abrasive
. If so, my most humble apologies
Flow dynamics are a walk in the park for some of the engineering crowd here. Keep in mind that I've never taken a formal physics course ..so other then using current flow as a model (DC) ..I'm lost in space (even without pondering too much beyond flatland)
Did I sound abrasive
Flow dynamics are a walk in the park for some of the engineering crowd here. Keep in mind that I've never taken a formal physics course ..so other then using current flow as a model (DC) ..I'm lost in space (even without pondering too much beyond flatland)
I doubt we are getting into turbulent flow. You have to calculate the Reynolds number to determine that. Often collecting all the data needed for that is worse than making the calculation. Most likely, most of the pepole doing it have a computer program that does all the work once they have the data.
I am guessing with the viscosity of the oil, the engine never develops turbulent flow except maybe in some of the bearing clearances.
I am guessing with the viscosity of the oil, the engine never develops turbulent flow except maybe in some of the bearing clearances.
- Status
Similar threads
